Abstract Riverine forests have high floristic diversity and are heterogeneous, even when they are near each other. Therefore, we aimed to compare three riverine forest remnants of Southern Brazil located in the Pampa biome regarding floristic and structural biodiversity, to: i) check whether the studied forest fragments maintain heterogeneity and high floristic richness as seen in riverine forests, even when close to each other, and ii) indicate the predominant successional groups in each remnant. A total of 81 sampling units were established, and all trees with diameter at breast height ≥ 15 cm were measured. We sampled 1,659 individuals, 67 species, and 34 families. The richness and structure of the three communities differed, confirming the high heterogeneity of riverine forests. One of the remnants had a higher predominance of pioneer species and individuals, which differentiated it from the other two. The latter, in turn, showed higher similarity in floristic and structural composition, with a predominance of secondary and late successional individuals and species. Differences in soil moisture, in the size and shape of fragments may be factors that contributed to the floristic and structural diversity observed. The remnants, although small and surrounded by monocultures, are heterogeneous and important for biodiversity conservation. Therefore i ii remnant 8 established 1 measured 1659 659 1,65 6 3 families differed two latter turn composition moisture observed monocultures conservation 165 65 1,6 16 1,

Abstract Bioindicator organisms, such as edaphic invertebrates, are constantly used to assess disturbance, as they exhibit responses such as reduced community and changes in diversity, affecting the local ecosystem. The aim of this study was to compare the impacts of disturbance on the edaphic invertebrate community in both a pasture area and a native forest area, during summer and winter. Samplings were conducted for nine days using pitfalls. Bray-Curtis analyses, NMDS, ANOSIM, and SIMPER were applied. There was difference in richness and diversity between areas and seasons. Native forest pitfalls had higher similarity in abundance and diversity in both seasons than pasture pitfalls. Specimens belonging to 20 orders were collected; of those, Collembola, Hymenoptera, Diptera, and Hemiptera had the highest number of individuals. Seasonal influence on the organisms was evident. The impact on edaphic invertebrate community located in the pasture area showed that native forest has higher complexity and structural stability.

Resumo: A Floresta com Araucária é uma formação vegetal única do planeta com ocorrência praticamente restrita ao bioma Mata Atlântica, no Sul e Sudeste brasileiro. Ela está imensamente fragmentada e sua área reduzida a uma fração mínima, de 2 a 13% da cobertura original, devido à intensa exploração antrópica. Nosso estudo avaliou a riqueza e a composição florística de samambaias e licófitas, no interior de três fragmentos de Floresta com Araucária, no Rio Grande do Sul, Brasil. Para o inventário florístico, foi demarcada uma parcela de 1 ha (100x100m) no interior de três fragmentos, os quais, por sua vez, foram classificados por tamanho: grande (246 ha - H1LF), médio (57 ha - H2MF) e pequeno (5,2 ha - H3SF). Foram registradas a forma de vida e o substrato preferencial das espécies ocorrentes até 4 m de altura do solo. Ao total, foram inventariadas 55 espécies, das quais apenas duas licófitas, distribuídas em 32 gêneros e 17 famílias. Considerando a área dos fragmentos, a riqueza registrada de espécies foi decrescente, sendo maior no H1LF (48), seguida do H2MF (33) e H3SF (29). Nos três sítios predominaram as espécies no substrato terrícola e a forma de vida hemicriptófita. Observamos que um hectare do fragmento florestal grande apresenta 65% mais espécies que o de um pequeno, considerando que a área total do fragmento menor representa apenas 2% da área do maior. Por outro lado, o hectare do fragmento pequeno contribui para a conservação de 17% das espécies de samambaias e licófitas ocorrentes em Floresta com Araucária no Brasil e 8% da riqueza total para o Estado do Rio Grande do Sul. A heterogeneidade na riqueza e na composição de espécies confere identidade florística própria a cada um dos interiores florestais estudados. Os nossos resultados destacam a necessidade da inclusão dos parâmetros botânicos analisados no manejo, na avaliação do grau de conservação e na manutenção biodiversidade vegetal da Floresta com Araucária.

Abstract: The Araucaria Forest is a unique plant formation, practically restricted to the Atlantic Forest biome, in the South and Southeast of Brazil. It is immensely fragmented and its area is reduced to a minimum fraction, from 13 to 2% of the original area, due to intense anthropic exploitation. Our study evaluated the richness and floristic composition of ferns and lycophytes within three Araucaria forest fragments, in Rio Grande do Sul, Brazil. For the floristic inventory, a parcel of 1 ha (100x100m) was demarcated inside three fragments, which were classified by size: large (246 ha - H1LF), medium (57 ha - H2MF) and small (5.2 ha - H3SF). Occurring species life forms and preferential substrates up to 4 meters above ground were recorded. In total, 55 species were catalogued, only two of which were lycophytes, distributed in 32 genera and 17 families. Considering the area of fragments, the recorded species richness has decreased, presenting greater numbers in H1LF (48), followed by H2MF (33), and H3SF (29). In the three sites, terrestrial substrate and the hemicryptophyte species life form predominated. We observed that one hectare of a larger forest fragment presented 65% more species than that of a smaller one, considering that the smaller fragment total area represents only 2% of the larger forest's area. On the other hand, one hectare of the smaller fragment contributed 17% to fern and lycophyte species conservation occurring in Brazilian Araucaria Forests, and 8% to the state of Rio Grande do Sul's total richness. The diverse heterogeneity and species composition grants floristic identity to each of the studied forest interiors. Our results highlight the need to include the botanical parameters here analyzed in management, conservation degree evaluation, and maintenance of Araucaria Forests plant biodiversity.

Resumo As matas ciliares são essenciais para a manutenção da biodiversidade e apresentam condições ecológicas favoráveis para o desenvolvimento de samambaias que são indicadoras de qualidade ambiental. Entretanto, essas matas vêm sofrendo impactos negativos relacionados principalmente à alta densidade demográfica, ao modelo de ocupação urbana e à expansão agrícola em áreas rurais. Neste trabalho, a qualidade ambiental da mata ciliar do rio Cadeia no Sul do Brasil foi avaliada utilizando parâmetros fitossociológicos da comunidade de samambaias do sub-bosque e o Protocolo de Avaliação Rápida da Qualidade de Hábitat (PARH). Foram alocadas 120 parcelas de 25 m2 distribuídas equitativamente entre três fragmentos (FI, FII, FIII). Foram inventariadas todas as espécies de samambaias herbáceas em cada unidade amostral. Para a análise da estrutura comunitária foram calculados os parâmetros de densidade, frequência, dominância relativa e o valor de importância da espécie (VI). A menor riqueza de espécies foi registrada no FIII (sete espécies). A composição florística é mais heterogênea e a riqueza é maior no FI no qual as parcelas apresentaram cobertura de plantas e a nota do PARH mais elevadas. A pontuação do PARH diminuiu com o aumento do grau de urbanização da matriz do entorno e os FI e FII foram classificados como naturais enquanto que o FIII como impactado. Considerando as quatro espécies com maior VI nos três fragmentos (que somam 69,11% do VI no FI, 78,36% no FII e 91,06% no FIII) pode-se afirmar que a estrutura comunitária de samambaias sofre uma simplificação com o aumento da antropização.

Abstract Riparian forests are essential to the maintenance of biodiversity and foster the development of ferns that are indicators of environmental quality. However, these forests have been degraded due mainly to high population density, pattern of urban settlement and agricultural expansion in rural areas. This study evaluated the environmental quality of riparian vegetation of the Cadeia River in Southern Brazil, using phytosociological parameters of the understory's fern community and a Rapid Assessment Protocol of Habitat Quality (RAPQH). One hundred and twenty plots of 25 m2 were equally distributed among three fragments (FI, FII, FIII). All species of herbaceous ferns were inventoried in each sample unit. We calculated parameters of density, frequency, relative dominance and importance value (IV) of species for the analysis of community structure. The lowest species richness was recorded at FIII (seven species). The floristic composition is more heterogeneous and richness is higher in FI, where the parcels had greater plant cover and RAPQH scores. The RAPQH score decreased with increasing degree of urbanization in the surrounding matrix and FI and FII were classified as "natural," while FIII was classified as "impacted." Considering the four species with the highest IV in the three fragments (totaling 69.11% of IV in the FI, 78.36% and 91.06% in FII and FIII respectively), it can be affirmed that the fern community structure is degraded with increasing anthropization.

Edge effects impact species richness and composition as a result of environmental changes caused by fragmentation. This study analyzed edge effects on a community of terrestrial ferns and lycophytes in an Araucaria forest in Brazil at sites subjected to differing edge conditions: (1) a site bordering a road running through the interior of a conservation unit, and (2) a site bordering an agricultural property. Twelve 10 × 10 m plots were selected at the edge and in the interior of each site, and accounted for a total of 48 plots. The edges had lost their characteristic floristic identity, suggesting that many species are sensitive to variations in environmental conditions. The edge effect had a negative impact on species richness as shown by the greater average numbers of fern and lycophyte species in forest interiors at both sites. The results showed that the forest fragments in contact with agricultural areas were subjected to more intense edge effects than the fragments bordering a road within a conservation unit.